axe.io

SPI interrupt driven Blinkinator

Wed, 01 Jun 2011 21:54:14 +1200

After some thought and discussion I managed to come up with a nice way to use the ATmega’s interrupt driven SPI to drive the clock source for the Blinkinator without it going all flickery with the introduction of the V-USB code. This is freaking awesome.

The Amp Hour Podcast

Tue, 24 May 2011 12:38:58 +1200

The Amp Hour Podcast:

I’ve been having a great time listening to The Amp Hour Podcast recently. The show follows the common “expert views and BS” format and is hosted by Chris Gammell and Dave Jones with occasional assistance from Jeff Keyzer, Jeri Ellsworth and other guests.

Keep the shows coming guys, they help keep me motivated and working on this project.

A small demonstration of the Blinkinator being correctly driven...

Thu, 12 May 2011 11:21:15 +1200

A small demonstration of the Blinkinator being correctly driven by the axe.io Thinkinator firmware, in this case being run off a standard Arduino Uno.

Blinkenator prototype test video.

Sat, 30 Apr 2011 20:38:57 +1200

Blinkenator prototype test video.

After being slowed down for a couple of weeks by moving house,...

Sat, 30 Apr 2011 20:29:28 +1200

Red!

Green!

Blue!

White!

After being slowed down for a couple of weeks by moving house, here are photos of my test code cycling through red, green, blue and white using the Allegro 6280 LED driver. It’s awesomely bright and despite my worries about using the ATmega328 to generate the clock source PWM seems smooth, so I’m not worried any more. Video coming soon.

Github repositories moved

Thu, 28 Apr 2011 11:49:10 +1200

I have switched from a single repository to a Github organisation which makes collaboration much easier and the repository less cluttered. Feel free to follow along.

V-USB-MIDI software USB MIDI AVR firmware

Thu, 07 Apr 2011 19:29:01 +1200

V-USB-MIDI software USB MIDI AVR firmware:

After a bit of browsing around I came across a the Objective Development V-USB project, which is a software implementation of a low-speed USB 1.1 device for AVR chips. This means that almost any AVR can be used as a USB interface without using the special (and more expensive) U version of the chip.

I will investigate this as a serious option for the MIDI expansion board for axe.io.

Assembled Thinkinator

Thu, 31 Mar 2011 10:46:00 +1300

Last night I spent an hour or so getting cuddly with my soldering iron and reemerged from the workshop with two assembled Thinkinator boards.

As you can probably tell from the photos there was a mix up between the footprint of the capacitors I bought and those on the board layout. I’ll see if I can pick up some matching caps before the next board run. In the meantime I have plenty to get on with.

You’ll also notice that the FTDI header isn’t attached yet, that’s because I’m waiting for an order to arrive from MindKits restocking my right-angle breakaway headers.

Tonight I plan to test the board by attempting to load the Arduino bootloader on via the ICSP header and loading on the Arduino blink example.

Also in the eye-candy department, here’s some photos of the a test-fit of a Blinkinator board to the HAPP arcade button:

I needed to do a little bit of filing around the edges of the cutaway sections to get a nice fit, but it looks great and doesn’t foul the button plunger or microswitch. The only problem is that the footprint for the output pins fouls with the outside of the plunger. The simplest solution to this is to simply solder the headers on to the bottom of the board instead. I will make a note to revise the board to fit better in the next version.

Purple meanies

Tue, 29 Mar 2011 20:40:47 +1300

Thanks to Lean, my boards have arrived. They were in the March 14th panel and arrived today. A 15 day turn around from emailing the board files to receiving the boards in the mail on the other side of the planet is just wonderful.

I’m hoping that I will get time to assemble some boards tomorrow night and start testing to see if I done good. I am reasonably confident that they will be fine.

Coincidentally today I received my AVR USB programmer from seeedstudio.com and will be able to burn the Arduino bootloader onto the ATMega328’s that I bought for this project. In short, we’re not far from seeing actual working blinkenlights.

First board order sent

Wed, 09 Mar 2011 10:32:00 +1300

I have just sent the first PCB order to Laen for fabbing. I have ordered twelve Blinkinator boards, three Thinkinator boards and three MIDI Expander boards (Laen requires boards to be ordered in multiples of three). I have branched the github repository so you can order the exact same parts and boards as me. I have also checked part lists into the same directory as the Eagle files.

In addition to the parts listed to assemble each of the boards I have a bunch of breakaway headers in single and double rows, some right angle single row headers and sockets, some of 6 pin crimp sockets and 28AWG wire for connecting the chain of Blinkinators. I plan on soldering each Blinkinator directly to it’s corresponding microswitch.

If you look at the Thinkinator board you will see that there is a 6 pin header labelled FTDI at the top left. This header is designed to match the Sparkfun FTDI basic breakout board and will allow uploading of new code without having to use the ICSP header and an AVR programmer (if your ATmega already contains the Arduino bootloader).

The MIDI and USB expander boards also have the same 6 pin right handle socket header as the board above to connect to the Thinkinator board allowing for a more modular and upgradable design.

I’m really excited to see my fresh new bright purple boards when they arrive and get soldering.

New version of Thinkinator board file

Mon, 07 Mar 2011 13:33:00 +1300

If you’ve been following along with the github repository you might have noticed that I have pushed a number of changes to the boards recently. After receiving my parts from DigiKey I printed out my board files to double check that everything fit. Good thing that I did because I discovered that the ATmega328 part in the Atmel library that ships with Eagle CAD is based around a 0.6” DIL32 package and the ATmega328’s I bought from DigiKey are a 0.3” DIL28 package! How I never noticed this before I don’t know, but I have to point out that I was in hospital at the time I did the board layout, so I blame it on that.

The resulting board file is so much smaller which should make board manufacture much cheaper whilst not resorting to any SMT components, making it much easier to solder.

GuitArduino: Open source MIDI guitar and the day by day process of it's development.

Fri, 04 Mar 2011 09:30:23 +1300

GuitArduino: Open source MIDI guitar and the day by day process of it's development.:

An interesting blog about converting a guitar into a MIDI controller using Arduino.

Apart from the courier delivery waking our sleeping baby boy, I...

Fri, 04 Mar 2011 09:05:15 +1300

Apart from the courier delivery waking our sleeping baby boy, I was very pleased to receive a care package from DigiKey with a bunch of parts needed to bring the project to reality. Next step; prototype on a breadboard and debug any issues before finally ordering the boards.

Blinkinator board test fit.

Wed, 02 Mar 2011 21:32:00 +1300

Today I printed out a copy of the latest version of the Blinkinator r1 board to test fit it to the button. As it happens I have to make a few minor tweaks to get a good fit and I’m really glad that I haven’t told Laen to order them!

As you can see I have changed the shape of the top hole in order to allow the microswitch retaining clips to pass through easier, although this will make it a less snug fit to the button, but nothing a spot of hot glue can’t fix.

The latest version of the board is available in the github repository.

Updated Blinkinator board

Wed, 02 Mar 2011 15:01:00 +1300

Having been able to spend some time with attacking buttons with my callipers I have been able to come up with a board design that should slip nicely in between the button housing and the microswitch putting the RGB LED directly behind the button plunger.

The latest version of the board and schematic are available in the github repository.

Moco for LUFA

Tue, 01 Mar 2011 11:00:00 +1300

Moco for LUFA:

Yoshitaka Kuwata over at morecat lab has written Moco for LUFA, a LUFA based firmware for the USB enabled U2 line of Atmel ATmega AVRs to enable them to act as a USB MIDI device reading and writing MIDI over it’s TTL serial TX and RX pins. This is an almost perfect fit for axe.io meaning that the entire Thinkinator board can be prototyped by a single Arduino UNO with the addition of pins to the empty second ICSP header and replacing the original serial firmware on the on-board 8U2.

The gift of buttons.

Sat, 26 Feb 2011 20:46:00 +1300

I was very excited to get home today and discover a package in my letterbox of transparent arcade buttons. They are every bit as awesome as I had hoped and a quick check with a ruler has given me the dimensions I need to do a proper board layout for the Blinkinator to fit in the gap between the button plunger and the microswitch.

Keep posted for new Blinkinator board files appearing soon.

Welcome to axe.io

Mon, 21 Feb 2011 12:58:00 +1300

Here’s the thing; I’m in this band, and due to the terrible prog rock nature of this band I needed more control over my tone than I was able to get just from my amplifier, so I invested in an iRig and a copy of Amplitube for iPhone. I was blown away by the quality of simulation available on my phone, but I needed more. Luckily, I won a competition over at MuzoBlog for a free copy of Amplitube 3 and I was in heaven. There was just one problem - I had no easy way to jump through presets or toggle various effects or stomps. Sure, there are plenty of options available, but they all seem a little pricey - and overkill - for what I wanted to do. That’s when the idea of axe.io came to me; I know how to write code, I know how to design products and I know how to hack electronics. Sounds like a dream project.

Keep an eye on the site, and on the github repository for updates. Please feel free to jump in and take part in the discussion here on the blog, via twitter and on github.